The connection between abnormal protein phosphorylation and the cause or consequence of diseases has been known for over 20 years. Accordingly, protein kinases have become a very important group of drug targets. (See Cohen, Nature, 1:309-315 (2002), Gaestel et al. Curr. Med. Chem. 14: 2214-223 (2007); Grimminger et al. Nat. Rev. Drug Disc. 9(12):956-970 (2010)). Various protein kinase inhibitors have been used clinically in the treatment of a wide variety of diseases, such as cancer and chronic inflammatory diseases, including rheumatoid arthritis and psoriasis. (See Cohen, Eur. J. Biochem., 268:5001-5010 (2001); Protein Kinase Inhibitors for the Treatment of Disease: The Promise and the Problems, Handbook of Experimental Pharmacology, Springer Berlin Heidelberg, 167 (2005)).
JNK is a ubiquitously expressed serine/threonine kinase belonging, together with ERK (extracellular-regulated kinase) and p38, to the family of mitogen-activated protein kinases (MAPKs). (Kyriakis J M, Sci. STKE (48):pe1 (2000); Whitmarsh A J, et al. Sci. STKE (1):pe1 (1999); Schramek H, News Physiol. Sci. 17:62-7 (2002); Ichijo H, Oncogene 18(45):6087-93 (1999)). MAPKs are important mediators of signal transduction from the cell surface to the nucleus, using phosphorylation cascades to generate a coordinated response by a cell to an external stimulus by phosphorylation of selected intracellular proteins, including transcription factors. Additionally, JNK also phosphorylates non-nuclear proteins, for example, IRS-1, and Bcl-2 family members. (Davis R J, Trends Biochem. Sci. 9(11):470-473 (1994); Seger R et al., FASEB J.; 9(9):726-35 (1995); Fanger G R et al., Curr. Opin. Genet. Dev.; 7(1):67-74 (1997)).
The elucidation of the intricacy of protein kinase pathways and the complexity of the relationship and interaction among and between the various protein kinases and kinase pathways highlights the importance of developing pharmaceutical agents capable of acting as protein kinase modulators, regulators or inhibitors that have beneficial activity on multiple kinases or multiple kinase pathways. The compound chemically named 2-(tert-butylamino)-4-((1R,3R,4R)-3-hydroxy-4-methylcyclohexylamino)-pyrimidine-5-carboxamide (alternatively named 2-[(1,1-dimethylethyl)amino]-4-[[(1R,3R,4R)-3-hydroxy-4-methylcyclohexyl]amino]-5-pyrimidinecarboxamide; and referred to herein as “Compound I”), an inhibitor of the JNK pathway, is disclosed in U.S. Patent Application Publication No. 2013/0029987, published on Jan. 31, 2013, International Pub. No. WO 2012/145569 and U.S. patent application Ser. No. 14/608,314, filed Jan. 29, 2015, the entireties of each of which are incorporated by reference herein. Accordingly, there remains a need for new processes for the preparation of Compound I.
Citation or identification of any reference in Section 2 of this application is not to be construed as an admission that the reference is prior art to the present application.